The processes of manufacturing a semiconductor device may include a process of forming a thin film such as a silicon oxide film on a substrate. For example, the thin film is formed by supplying a precursor gas containing silicon, an oxidizing gas or the like to the substrate. In this case, a catalytic gas may be used to form a thin film at a relatively low temperature thereby improving a thermal budget or the like of the semiconductor device.
In addition, in forming a thin film on a substrate carbon or the like may be added to the thin film to enhance the film quality such as a resistance to wet etching.
However, under a relatively low temperature condition, it may be difficult to introduce carbon into a film, which results in failing to obtain a sufficient carbon concentration or failing to control the carbon concentration with high precision, or the like. Due to these problems, it is impossible to form a thin film having sufficient etching resistance, for example.